JP4540650B2 - Imaging device - Google Patents

Description

  The present invention relates to a photographing apparatus such as a digital still camera provided with a solid-state imaging device composed of a CCD or the like.

In recent years, digital still cameras having a solid-state imaging device composed of a CCD or the like have become widespread.
FIG. 2 shows a configuration of an interline transfer type solid-state imaging device (1) used in a digital still camera. In the solid-state imaging device (1), a color filter array is provided on a plurality of photosensors arranged in a matrix to form an imaging surface composed of a plurality of pixels (11), and a plurality of pixels arranged in the vertical direction. A plurality of vertical registers (12) for transferring the charges of the pixels (11) in the column in the vertical direction, and a horizontal register (13) for outputting the charges transferred by these vertical registers (12) in a cycle of one horizontal period; Is provided.

The solid-state imaging device (1) has an input terminal 8 for a first vertical transfer pulse Vφ1 having a first phase, an input terminal 7 for a second vertical transfer pulse Vφ2 having a second phase, and a third phase. A pair of third vertical transfer pulses Vφ3A and Vφ3B, input terminals 6 and 5, an input terminal 4 of a fourth vertical transfer pulse Vφ4 having a fourth phase, and a pair of fifth vertical transfer pulses Vφ5A and Vφ5B having a fifth phase Input terminals 3 and 2 and an input terminal 1 for a sixth vertical transfer pulse Vφ6 having a sixth phase. By supplying each vertical transfer pulse to these input terminals, the electric charge accumulated in the vertical register (12) is transferred to the horizontal register (13).
The solid-state imaging device (1) includes a pair of first horizontal transfer pulses Hφ1A and Hφ1B input terminals 21 and 16 and a pair of second horizontal transfer pulses Hφ2A obtained by inverting the first horizontal transfer pulse, respectively. Hφ2B input terminals 22 and 17 are provided. By supplying each horizontal transfer pulse to these input terminals, the charges transferred from the vertical register (12) to the horizontal register (13) are output to the outside.
Further, the solid-state imaging device (1) is provided with an input terminal 19 for a sub-pulse φSUB for executing an electronic shutter operation for sweeping out charges accumulated in the pixels before the exposure of the imaging surface.

In a conventional digital still camera, it is possible to set a monitor mode in which an image (through image) photographed by the solid-state imaging device (1) is displayed on a monitor with a period of 1/30 seconds.
FIG. 8 shows an operation when the shutter button is pressed in a monitor mode set in a conventional digital still camera, and vertical transfer pulses Vφ1 to Vφ6 and horizontal transfer pulses Hφ1A and Hφ1B supplied to the solid-state imaging device. , Hφ2A, Hφ2B, and sub-pulse φSUB. In FIG. 8, SHT is a shutter pulse generated when the shutter button is pressed, and VD is a vertical synchronization pulse. The vertical transfer pulse, horizontal transfer pulse, and sub-pulse are rectangular pulses, and one block of the horizontal transfer pulse in FIG. 8 represents a series of horizontal transfer pulses.
As illustrated, the solid-state imaging device includes a first vertical transfer pulse Vφ1, a second vertical transfer pulse Vφ2, a third vertical transfer pulse Vφ3A, Vφ3B, a fourth vertical transfer pulse Vφ4, a fifth vertical transfer pulse Vφ5A, Vφ5B, and Six vertical transfer pulses Vφ6 are continuously supplied, and a series of first horizontal transfer pulses Hφ1A and Hφ1B and second horizontal transfer pulses Hφ2A and Hφ2B are intermittently supplied in a cycle of one vertical period. As a result, the charge accumulated in the pixel is transferred as will be described later.

  When the shutter button is pressed, in the first vertical period (# 1V), a series of sub-pulses φSUB is supplied to the solid-state imaging device, and the charge accumulated in the pixels is swept away, and then the imaging surface is exposed. It is. Subsequently, in the second vertical period (# 2V), the charges accumulated in the pixels by the exposure performed in the first vertical period are transferred, and the exposure time and focus adjustment are performed based on the image signal obtained thereby. The value calculation starts. In addition, after a series of sub-pulses φSUB is supplied to the solid-state imaging device and the charges accumulated in the pixels are swept away, the imaging surface is exposed.

Next, in the third vertical period (# 3V), after the calculation is continuously performed, the exposure time and the focus adjustment value obtained by the calculation are set. In addition, the charge accumulated in the pixels by the exposure performed in the second vertical period is transferred, and the calculation of the exposure time and the focus adjustment value is started based on the image signal obtained thereby. Further, after a series of sub-pulses φSUB is supplied to the solid-state imaging device and the charges accumulated in the pixels are swept away, the imaging surface is exposed.
Subsequently, in the fourth vertical period (# 4V), after the calculation is continuously performed, the exposure time and the focus adjustment value obtained by the calculation are set. In addition, the charge accumulated in the pixels by the exposure performed in the third vertical period is transferred, and the calculation of the exposure time and the focus adjustment value is started based on the image signal obtained thereby. Further, after a series of sub-pulses φSUB is supplied to the solid-state imaging device and the charges accumulated in the pixels are swept away, the imaging surface is exposed. At this time, the exposure time and focus adjustment value set in the third vertical period are reflected. Similarly, exposure, transfer, calculation and setting are performed in parallel in one vertical period.

  In the above-described conventional digital still camera, when the shutter button is pressed, a series of shooting operations of exposure, transfer, calculation and setting are executed by shifting by one vertical period every three vertical periods as described above, so that an optimal exposure time is obtained. When the focus adjustment value is obtained, a photographing operation for image recording is started.

In the conventional digital still camera, the calculation time for obtaining the photographing conditions such as the exposure time and the focus adjustment value exceeds one vertical period, whereas FIG. 9 shows the conventional digital still camera in which the calculation time is less than one vertical period. The operation when the shutter button is pressed in the camera, and vertical transfer pulses Vφ1 to Vφ6, horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B, and sub-pulse φSUB supplied to the solid-state imaging device are shown. In FIG. 9, SHT is a shutter pulse generated when the shutter button is pressed, and VD is a vertical synchronization pulse. The vertical transfer pulse, horizontal transfer pulse, and sub-pulse are rectangular pulses, and one block of the horizontal transfer pulse in FIG. 9 represents a series of horizontal transfer pulses.
As illustrated, the solid-state imaging device includes a first vertical transfer pulse Vφ1, a second vertical transfer pulse Vφ2, a third vertical transfer pulse Vφ3A, Vφ3B, a fourth vertical transfer pulse Vφ4, a fifth vertical transfer pulse Vφ5A, Vφ5B, and 6 vertical transfer pulses Vφ6 are continuously supplied to the vertical register, and a series of first horizontal transfer pulses Hφ1A and Hφ1B and second horizontal transfer pulses Hφ2A and Hφ2B are intermittently supplied in a cycle of one vertical period. . As a result, the charge accumulated in the pixel is transferred as will be described later.

  When the shutter button is pressed, in the first vertical period (# 1V), a series of sub-pulses φSUB is supplied to the solid-state imaging device, and the charge accumulated in the pixels is swept away, and then the imaging surface is exposed. It is. Next, in the second vertical period (# 2V), the charge accumulated in the pixels by the exposure performed in the first vertical period is transferred, and the exposure time and focus adjustment are performed based on the image signal obtained thereby. The value is calculated, and the exposure time and focus adjustment value obtained by the calculation are set. In addition, after a series of sub-pulses φSUB is supplied to the solid-state imaging device and the charges accumulated in the pixels are swept away, the imaging surface is exposed.

  Subsequently, in the third vertical period (# 3V), the charge accumulated in the pixels by the exposure performed in the second vertical period is transferred, and the exposure time and focus are based on the image signal obtained thereby. The adjustment value is calculated, and the exposure time and focus adjustment value obtained by the calculation are set. In addition, after a series of sub-pulses φSUB is supplied to the solid-state imaging device and the charges accumulated in the pixels are swept away, the imaging surface is exposed. At this time, the exposure time and the focus adjustment value set in the second vertical period are reflected. Similarly, exposure, transfer, calculation and setting are performed in parallel in one vertical period.

  In the above-described conventional digital still camera in which the calculation time is less than one vertical period, when the shutter button is pressed, the series of shooting operations of exposure, transfer, calculation and setting are shifted by two vertical periods by one vertical period as described above. When the optimum exposure time and focus adjustment value are obtained, the photographing operation for image recording is started.

A solid-state image sensor driving timing generator that calculates the number of pulses of the charge sweep-out signal XSUB by subtracting the exposure time from the number of horizontal lines per field and outputs the charge sweep-out signal XSUB by the calculated number of pulses. It has been proposed (see Patent Document 1).
In addition, a solid-state imaging device has been proposed in which the number of electronic shutter pulses φSUB is set so that the exposure time in each field is the same when the frame readout mode is set (see Patent Document 2).
JP-A-10-136271 [H04N5 / 335] Japanese Patent Laid-Open No. 2001-268452 [H04N5 / 335]

However, in the conventional digital still camera, as shown in FIGS. 8 and 9, a series of photographing operations are performed while being shifted by one vertical period, so that the sub-pulse φSUB is solid-state imaged during the entire period in which the series of photographing operations are repeated. The exposure operation is performed by being supplied to the element, and the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B are supplied to the solid-state imaging device to perform the transfer operation, thereby increasing the power consumption. was there.
An object of the present invention is to provide a photographing apparatus such as a digital still camera that consumes less power than conventional ones.

  Therefore, as a result of intensive studies to solve the above problems, the present inventor does not need to repeat a series of photographing operations in a short cycle of one vertical period when an image photographed by a solid-state imaging device is not displayed on the monitor. That led to the completion of the present invention.

  A first imaging device according to the present invention includes a solid-state imaging device having an imaging surface including a plurality of pixels, a driving device that drives the solid-state imaging device, and a control device that controls the operation of the driving device. The solid-state imaging device can receive the sub-pulse supplied from the driving device and sweep the charge accumulated in the pixels to the outside. The driving device supplies the sub-pulse to the solid-state imaging device. It has. The imaging apparatus performs a series of imaging operations including an exposure operation for exposing the imaging surface after supplying a sub-pulse to the solid-state imaging device and sweeping out the electric charge accumulated in the pixels to the outside. The control device repeats at a period equal to or longer than the period during which the control device performs a sub-pulse from the drive device to the solid-state image sensor during a period in which the exposure operation included in the series of imaging operations is not performed. Sub-pulse stop means for stopping the supply of.

  In the first imaging apparatus according to the present invention, a series of imaging operations including an exposure operation is repeated at a period that is the same as or longer than the period during which the series of imaging operations are performed. Therefore, the exposure operation included in the series of shooting operations before and after the series of shooting operations is not performed during the period when the exposure operation included in the series of shooting operations is not performed. The sub-pulse supply from the apparatus to the solid-state image sensor is stopped. As a result, since the sub-pulse supply is stopped during the period when the exposure operation included in the series of imaging operations is not performed, the conventional digital still camera in which the sub-pulse is supplied during the entire period in which the series of imaging operations are repeated is used. In comparison, the number of sub-pulse outputs is reduced, and as a result, power consumption is reduced.

  The control device may employ a configuration including sub-pulse reduction means for reducing the number of sub-pulses supplied from the drive device to the solid-state image sensor during a period when no exposure operation is performed, instead of the sub-pulse stop means. . In this manner, power consumption can be reduced by simply reducing the number of subpulses supplied without completely stopping the supply of subpulses.

  Specifically, the solid-state imaging device includes a plurality of vertical registers that receive a vertical transfer pulse from the driving device and transfer charges of pixels in a plurality of columns arranged in the vertical direction in the vertical direction, and the driving device And a horizontal register that outputs the charges transferred by the plurality of vertical registers in response to the supply of the horizontal transfer pulse from the plurality of vertical registers, and the pulse supply circuit of the driving device supplies the vertical transfer pulse and the horizontal transfer pulse to the solid-state imaging device. In the series of photographing operations, a vertical transfer pulse and a horizontal transfer pulse are supplied to the solid-state imaging device to transfer charges of a plurality of columns of pixels arranged in a vertical direction to a horizontal register. A transfer operation for outputting to the outside from the horizontal register, and the control device drives the drive during a period when the transfer operation included in the series of photographing operations is not performed. And comprising a transfer pulse stopping means for stopping the supply of the vertical transfer pulses and / or horizontal transfer pulse for put al the solid-state imaging device.

  In the specific configuration, the transfer operation included in the series of shooting operations before and after the series of shooting operations is not performed during the period when the transfer operation included in the series of shooting operations is not performed. The supply of the vertical transfer pulse and / or the horizontal transfer pulse from the driving device to the solid-state image sensor is stopped. As described above, since the supply of the vertical transfer pulse and / or the horizontal transfer pulse is stopped during the period in which the transfer operation included in the series of imaging operations is not performed, the vertical transfer pulse is applied to the entire period in which the series of imaging operations are repeated. In addition, the number of output times of the vertical transfer pulse and / or the horizontal transfer pulse is reduced as compared with the conventional digital still camera to which the horizontal transfer pulse is supplied, and as a result, the power consumption is further reduced.

  A second imaging device according to the present invention includes a solid-state imaging device, a driving device that drives the solid-state imaging device, and a control device that controls the operation of the driving device. An imaging surface comprising a plurality of pixels arranged in a shape, and a plurality of vertical registers that transfer the charges of pixels in a plurality of columns arranged in the vertical direction in response to the supply of a vertical transfer pulse from the driving device; A horizontal register that outputs a charge transferred by the plurality of vertical registers in response to a supply of a horizontal transfer pulse from the driving device, and the driving device supplies a vertical transfer pulse and a horizontal transfer pulse to the solid-state imaging device. A pulse supply circuit is provided. Then, the imaging apparatus supplies vertical transfer pulses and horizontal transfer pulses to the solid-state imaging device, transfers charges of pixels in a plurality of columns arranged in the vertical direction to a horizontal register, and outputs the charges from the horizontal register to the outside. A series of shooting operations including a transfer operation is repeated at a period equal to or longer than a period during which the series of shooting operations are performed, and the control device performs a transfer operation included in the series of shooting operations. Transfer pulse stopping means for stopping the supply of vertical transfer pulses and / or horizontal transfer pulses from the driving device to the solid-state imaging device during a period when the driving is not performed is provided.

  In the second imaging apparatus according to the present invention, a series of imaging operations including a transfer operation is repeated at a period that is the same as or longer than the period during which the series of imaging operations are performed. Therefore, during the period when the transfer operation included in the series of shooting operations is not performed, the transfer operation included in the series of shooting operations before and after the series of shooting operations is not performed. The supply of vertical transfer pulses and / or horizontal transfer pulses to the solid-state imaging device from the apparatus is stopped. As described above, since the supply of the vertical transfer pulse and / or the horizontal transfer pulse is stopped during the period in which the transfer operation included in the series of imaging operations is not performed, the vertical transfer pulse is applied to the entire period in which the series of imaging operations are repeated. In addition, the number of sub-pulse outputs is reduced as compared with a conventional digital still camera to which a horizontal transfer pulse is supplied, and as a result, power consumption is reduced.

  According to the first and second imaging apparatuses according to the present invention, power consumption can be reduced as compared with the conventional art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention applied to a digital still camera equipped with a solid-state imaging device made up of a CCD will be specifically described below based on three examples. An “electronic shutter pulse” may be used as another name for the following “sub-pulse” and “sub-timing pulse”.
First Embodiment A digital still camera according to the present invention comprises a solid-state imaging device (1) shown in FIG. 2, and the solid-state imaging device (1) includes a first vertical transfer pulse Vφ1 having a first phase. Input terminal 8, input terminal 7 of second vertical transfer pulse Vφ2 having a second phase, input terminals 6, 5, and a pair of third vertical transfer pulses Vφ3A and Vφ3B having a third phase. Input terminal 4 of fourth vertical transfer pulse Vφ4 having, input terminals 3 and 2 of a pair of fifth vertical transfer pulses Vφ5A and Vφ5B having a fifth phase, and input of sixth vertical transfer pulse Vφ6 having a sixth phase. A terminal 1 is provided.
The solid-state imaging device (1) includes a pair of first horizontal transfer pulses Hφ1A and Hφ1B input terminals 21 and 16 and a pair of second horizontal transfer pulses Hφ2A and Hφ2B formed by inverting the first horizontal transfer pulse. Input terminals 22 and 17 are provided.
Further, the solid-state imaging device (1) is provided with an input terminal 19 for a sub pulse φSUB for executing an electronic shutter operation.

  FIG. 1 shows the configuration of a digital still camera according to the present invention. A vertical transfer drive circuit (2) and a horizontal transfer drive circuit (3) are connected to the solid-state imaging device (1), and the first vertical transfer pulse Vφ1 and the second transfer pulse from the vertical transfer drive circuit (2). A vertical transfer pulse Vφ2, a pair of third vertical transfer pulses Vφ3A, Vφ3B, a fourth vertical transfer pulse Vφ4, a pair of fifth vertical transfer pulses Vφ5A, Vφ5B, a sixth vertical transfer pulse Vφ6, and a sub-pulse φSUB are supplied. A pair of first horizontal transfer pulses Hφ1A and Hφ1B and a pair of second horizontal transfer pulses Hφ2A and Hφ2B are supplied from the transfer drive circuit (3).

A timing generator (TG) (4) is connected to the vertical transfer drive circuit (2) and the horizontal transfer drive circuit (3). In the timing generator (4), a first vertical timing pulse, a second vertical timing pulse, a pair of third vertical timing pulses, a fourth vertical timing pulse, a pair of fifth vertical timing pulses, a sixth vertical timing pulse, a charge readout pulse And sub-timing pulses are generated, and these pulses are supplied to the vertical transfer driving circuit (2). Also, a pair of first horizontal timing pulses and a pair of second horizontal timing pulses are generated, and these pulses are supplied to the horizontal transfer drive circuit (3).
In the vertical transfer driving circuit (2), the first to sixth vertical transfer pulses Vφ1, Vφ2, Vφ3A, Vφ3B, Vφ4, Vφ5A from the charge readout pulse obtained from the timing generator (4) and the first to sixth vertical timing pulses, Vφ5B and Vφ6 are created, and the sub-pulse φSUB is created by amplifying the sub-timing pulse, and the created pulse is supplied to the solid-state imaging device (1). On the other hand, the horizontal transfer driving circuit (3) amplifies the pair of first horizontal timing pulses and the pair of second horizontal timing pulses obtained from the timing generator (4) to thereby generate a pair of first horizontal transfer pulses Hφ1A, Hφ1B and A pair of second horizontal transfer pulses Hφ2A and Hφ2B are generated, and these pulses are supplied to the solid-state imaging device (1).

  The CCD output obtained from the solid-state imaging device (1) is a predetermined image processing such as a CDS / AGC circuit (5) comprising a sampling unit CDS and a gain control unit AGC, an A / D converter (6), and compression processing. After passing through the image processing circuit (7) for performing the above, it is output to the subsequent circuit. Sampling signals SHP and SHD for sampling the CCD output are supplied from the timing generator (4) to the CDS / AGC circuit (5), and from the timing generator (4) to the A / D converter (6). A sampling signal ADCK for A / D conversion is supplied.

A control circuit (8) is connected to the timing generator (4) and the image processing circuit (7), and a shutter button (9) is connected to the control circuit (8). The control circuit (8) controls the output operation of the vertical timing pulse to the vertical transfer driving circuit (2) of the timing generator (4) and the output operation of the horizontal timing pulse to the horizontal transfer driving circuit (3).
The control circuit (8) acquires the image signal (luminance signal) of the effective area of the solid-state imaging device (1) from the image processing circuit (7), detects the signal level of the image signal, and outputs the detection result. Based on this, an exposure time and a focus adjustment value are calculated. In accordance with the calculation result, the sub-timing pulse output operation to the vertical transfer driving circuit (2) of the timing generator (4) is controlled, and the operation of the lens driving circuit (not shown) is controlled.

  In the digital still camera of this embodiment, the monitor mode can be set as in the conventional case. FIG. 3 shows the shutter button (9) in the state where the monitor mode is set in the digital still camera of this embodiment. The operation when the button is pressed, and the vertical transfer pulses Vφ1 to Vφ6, the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B, and the sub-pulse φSUB supplied to the solid-state imaging device (1) are shown. In FIG. 3, SHT is a shutter pulse generated when the shutter button (9) is pressed, and VD is a vertical synchronization pulse. The vertical transfer pulse, horizontal transfer pulse, and sub pulse are rectangular pulses, and one block of the horizontal transfer pulse in FIG. 3 represents a series of horizontal transfer pulses.

When the shutter button (9) is pressed, a series of sub-pulses φSUB is supplied to the solid-state image sensor in the first vertical period (# 1V), and the charge accumulated in the pixels is swept away. Exposure is performed. Subsequently, in the second vertical period (# 2V), the first vertical transfer pulse Vφ1, the second vertical transfer pulse Vφ2, the third vertical transfer pulses Vφ3A, Vφ3B, the fourth vertical transfer pulse Vφ4, and the fifth vertical transfer pulse Vφ5A. , Vφ5B and the sixth vertical transfer pulse Vφ6 are supplied to the vertical register, and the first horizontal transfer pulses Hφ1A and Hφ1B and the second horizontal transfer pulses Hφ2A and Hφ2B are supplied to the horizontal register and accumulated in the pixels by the exposure. The transferred charge is transferred, and the calculation of the exposure time and the focus adjustment value is started based on the image signal obtained thereby. At this time, the supply of the sub pulse φSUB to the solid-state imaging device (1) is stopped.
Next, in the third vertical period (# 3V), after the calculation is continuously performed, the exposure time and the focus adjustment value obtained by the calculation are set. At this time, the supply of the vertical transfer pulses Vφ1 to Vφ6, the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B and the sub-pulse φSUB to the solid-state imaging device (1) is stopped.

Subsequently, in a fourth vertical period (# 4V), a series of sub-pulses φSUB is supplied to the solid-state imaging device (1) to sweep away the charges accumulated in the pixels, and then the imaging surface is exposed. At this time, the exposure time and the focus adjustment value set as described above are reflected. Further, the supply of the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B to the solid-state imaging device (1) is stopped. Next, in the fifth vertical period (# 5V), vertical transfer pulses Vφ1 to Vφ6 and horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B are supplied to the solid-state imaging device (1) and accumulated in the pixels by the exposure. The charge transfer is performed, and the calculation of the exposure time and the focus adjustment value is started based on the image signal obtained thereby. At this time, the supply of the sub pulse φSUB to the solid-state imaging device (1) is stopped.
Next, in the sixth vertical period (# 6V), after the calculation is continuously performed, the exposure time and the focus adjustment value obtained by the calculation are set. At this time, the supply of the vertical transfer pulses Vφ1 to Vφ6, the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B and the sub-pulse φSUB to the solid-state imaging device (1) is stopped. Thereafter, exposure, transfer, calculation and setting are repeated in the same manner as in the fourth to sixth vertical periods.

  In the digital still camera of the present embodiment, when the shutter button (9) is pressed, a series of shooting operations of exposure, transfer, calculation and setting as described above is the same as the period during which the series of shooting operations are performed. The operation is repeated at a period, and when an optimum exposure time and focus adjustment value are obtained, a photographing operation for image recording is started. In the period in which the series of photographing operations are repeated in this way, during the period in which the exposure operation is not performed, the supply of the sub-pulse φSUB to the solid-state imaging device (1) is stopped and the transfer operation is not performed. The supply of the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B to the solid-state imaging device (1) is stopped.

FIG. 4 shows a procedure executed by the control circuit (8) when the monitor mode is set. First, in step S1, it is determined whether or not the shutter button (9) is pressed, and it is determined as NO. If YES in step S2, a normal monitor display control operation is executed, and the process returns to step S1. By repeating the process of step S2, an image photographed by the solid-state imaging device (1) is displayed on the monitor at a period of 1/30 seconds, for example.
On the other hand, when the shutter button (9) is pressed and it is determined as YES in step S1, the process proceeds to step S3 to instruct the timing generator (4) to output a sub-timing pulse. In response to the command, the timing generator (4) outputs a sub-timing pulse to the vertical transfer driving circuit (2) in a period excluding the calculated exposure time in one vertical period, and vertical transfer driving is performed accordingly. The circuit (2) supplies a sub pulse to the solid-state imaging device (1). As a result, after the charge accumulated in the pixel is swept out to the outside, the imaging surface is exposed for the exposure time.

  Next, in step S4, it is determined whether or not the photographing conditions such as the exposure time and the focus adjustment value set at that time are optimal based on the image signal. If it is determined no, the process proceeds to step S5. Thus, the timing generator (4) is instructed to output the vertical timing pulse and the horizontal timing pulse, and is also instructed to stop the output of the sub-timing pulse. In response to the output command, the timing generator (4) outputs a vertical timing pulse to the vertical transfer driving circuit (2) and also outputs a horizontal timing pulse to the horizontal transfer driving circuit (3). The vertical transfer drive circuit (2) supplies a vertical transfer pulse to the solid-state image sensor (1), and the horizontal transfer drive circuit (3) supplies a horizontal transfer pulse to the solid-state image sensor (1). As a result, the charges accumulated in the pixels by exposure are transferred to the horizontal register (13) via the vertical register (12) and output to the outside. In response to the output stop command, the timing generator (4) stops outputting the sub-timing pulse to the vertical transfer driving circuit (2), thereby stopping the supply of the sub-pulse to the solid-state imaging device (1). .

  Subsequently, in step S6, calculation for obtaining the exposure time and the focus adjustment value is started, and in step S7, the timing generator (4) is instructed to stop the output of the vertical timing pulse and the horizontal timing pulse. In response to the command, the timing generator (4) stops the output of the vertical timing pulse to the vertical transfer driving circuit (2) and the horizontal timing pulse to the horizontal transfer driving circuit (3). The supply of vertical transfer pulses and horizontal transfer pulses to 1) is stopped. Next, in step S8, after the calculation is completed, the exposure time and focus adjustment value obtained by the calculation are set, and then the process returns to step S3. The processes in steps S3, S5, and S7 are sequentially performed every time one vertical period elapses. By repeating the processes in steps S3 to S8, as shown in FIG. 3, exposure, transfer, and calculation are performed. And a series of shooting operations consisting of settings are repeated at a cycle of three vertical periods.

  Thereafter, when it is determined in step S4 of FIG. 4 that the set shooting conditions such as exposure time and focus adjustment value are optimum, the process proceeds to step S9 and the shooting control operation for image recording is performed. After execution, the process returns to step S1. As a result, an image taken by the solid-state imaging device (1) is recorded on the recording medium.

In the digital still camera of this embodiment, as shown in FIG. 3, the exposure time and the calculation time of the focus adjustment value are longer than one vertical period, and the exposure operation is not performed within a period in which a series of photographing operations are repeated. In addition, the supply of the sub-pulse φSUB to the solid-state image pickup device (1) is stopped, and the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B to the solid-state image pickup device (1) during the period when the transfer operation is not performed. As shown in FIG. 8, the conventional digital still camera in which the sub-pulse φSUB, the vertical transfer pulses Vφ1 to Vφ6, and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B are supplied to the solid-state imaging device as shown in FIG. Power consumption is reduced compared to.
Even when using a viewfinder that does not display an image photographed by the solid-state imaging device (1) on the monitor, the series of photographing operations is performed at a cycle of three vertical periods as in the case of pressing the shutter button (9). Repeatedly, the supply of the sub-pulse is stopped during the period when the exposure operation is not performed, and the supply of the vertical transfer pulse and the horizontal transfer pulse is stopped during the period when the transfer operation is not performed.

Second Embodiment In the digital still camera of the first embodiment, the calculation time of the exposure time and the focus adjustment value exceeds one vertical period as shown in FIG. The time is less than one vertical period.
FIG. 5 shows the operation when the shutter button is pressed in the digital still camera of the present embodiment, the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B supplied to the solid-state imaging device (1). , And sub-pulse φSUB. Note that SHT in FIG. 5 is a shutter pulse generated when the shutter button is pressed, and VD is a vertical synchronization pulse. The vertical transfer pulse, the horizontal transfer pulse, and the sub-pulse are rectangular pulses, and one block of the horizontal transfer pulse in FIG. 5 represents a series of horizontal transfer pulses.

  When the shutter button is pressed, a series of sub-pulses φSUB is supplied to the solid-state imaging device (1) in the first vertical period (# 1V), and the charge accumulated in the pixels is swept away, and then the imaging surface is scanned. Exposure is performed. Next, in the second vertical period (# 2V), the first vertical transfer pulse Vφ1, the second vertical transfer pulse Vφ2, the third vertical transfer pulses Vφ3A, Vφ3B, the fourth vertical transfer pulse Vφ4, and the fifth vertical transfer pulse Vφ5A. , Vφ5B and the sixth vertical transfer pulse Vφ6 are supplied to the vertical register, and the first horizontal transfer pulses Hφ1A and Hφ1B and the second horizontal transfer pulses Hφ2A and Hφ2B are supplied to the horizontal register and accumulated in the pixels by the exposure. The transferred charge is transferred. Further, the exposure time and focus adjustment value are calculated based on the image signal thus obtained, and the exposure time and focus adjustment value obtained by the calculation are set.

  Subsequently, in the third vertical period (# 3V), a series of sub-pulses φSUB is supplied to the solid-state imaging device (1), and the charges accumulated in the pixels are swept away, and then the imaging surface is exposed. At this time, the exposure time and the focus adjustment value set as described above are reflected. Further, the supply of the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B to the solid-state imaging device (1) is stopped. Next, in the fourth vertical period (# 4V), vertical transfer pulses Vφ1 to Vφ6 and horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B are supplied to the solid-state imaging device (1) and accumulated in the pixels by the exposure. Charge transfer is performed. Further, the exposure time and focus adjustment value are calculated based on the image signal thus obtained, and the exposure time and focus adjustment value obtained by the calculation are set. Thereafter, exposure, transfer, calculation and setting are repeated in the same manner as in the third vertical period and the fourth vertical period.

  In the digital still camera of the present embodiment, when the shutter button (9) is pressed, a series of photographing operations of exposure, transfer, calculation and setting as described above is the same as the two vertical periods during which the series of photographing operations are performed. The operation is repeated at a period, and when an optimum exposure time and focus adjustment value are obtained, a photographing operation for image recording is started. In the period in which the series of photographing operations are repeated in this way, during the period in which the exposure operation is not performed, the supply of the sub-pulse φSUB to the solid-state imaging device (1) is stopped and the transfer operation is not performed. The supply of the vertical transfer pulses Vφ1 to Vφ6 and the horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, Hφ2B to the solid-state imaging device (1) is stopped. Therefore, as shown in FIG. 9, the power consumption is lower than that of a conventional digital still camera in which the sub-pulse φSUB, vertical transfer pulses Vφ1 to Vφ6, and horizontal transfer pulses Hφ1A, Hφ1B, Hφ2A, and Hφ2B are supplied to the solid-state imaging device. To reduce.

Third Embodiment As shown in FIG. 6, the digital still camera of the third embodiment employs an operation for reducing the number of outputs of the sub-pulse φSUB in place of the operation for stopping the supply of the sub-pulse φSUB in the first embodiment. In step S5 ′ shown in FIG. 7, a sub-timing pulse output number reduction command is issued. This also reduces power consumption compared to conventional digital still cameras.

Each part configuration of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.
For example, in the above-described embodiment, the present invention is implemented in a digital still camera including the six-phase drive type solid-state image pickup device (1) shown in FIG. The present invention can also be implemented in a digital still camera including a phase drive type solid-state imaging device.

It is a block diagram showing the structure of the digital still camera which implemented this invention. It is a block diagram showing the structure of a solid-state image sensor. 3 is a timing chart showing an operation when a shutter button is pressed in the digital still camera of the first embodiment, and vertical transfer pulses, horizontal transfer pulses, and sub-pulses supplied to the solid-state imaging device. It is a flowchart showing the operation | movement of the monitor mode in 1st Example. It is a timing chart showing the operation | movement when a shutter button is pressed in the digital still camera of 2nd Example, and the vertical transfer pulse, horizontal transfer pulse, and subpulse which are supplied to a solid-state image sensor. It is a timing chart showing the operation | movement when a shutter button is pressed in the digital still camera of 3rd Example, and the vertical transfer pulse, horizontal transfer pulse, and subpulse which are supplied to a solid-state image sensor. It is a flowchart showing the operation | movement of the monitor mode in 3rd Example. It is a timing chart showing the operation | movement when a shutter button is pressed in the conventional digital still camera, and the vertical transfer pulse, horizontal transfer pulse, and subpulse which are supplied to a solid-state image sensor. It is a timing chart showing the operation | movement when a shutter button is pressed in the other conventional digital still camera, and the vertical transfer pulse, horizontal transfer pulse, and subpulse which are supplied to a solid-state image sensor.

Explanation of symbols

(1) Solid-state image sensor
(11) Pixel
(12) Vertical register
(13) Horizontal register
(2) Vertical transfer drive circuit
(3) Horizontal transfer drive circuit
(4) Timing generator
(5) CDS / AGC circuit
(6) A / D converter
(7) Image processing circuit
(8) Control circuit
(9) Shutter button

Claims (4)

A solid-state imaging device having an imaging surface composed of a plurality of pixels; a driving device that drives the solid-state imaging device; and a control device that controls the operation of the driving device. The solid-state imaging device receives a sub-pulse from the driving device. In the imaging apparatus including a pulse supply circuit that supplies a sub-pulse to the solid-state imaging device. By supplying a sub-pulse to the element and sweeping out the charge accumulated in the pixel to the outside, an exposure operation for exposing the imaging surface, a transfer operation for transferring the charge accumulated in the pixel by exposure to the outside, and a transfer operation A series of shooting operations including a calculation operation for calculating an exposure time and / or a focus adjustment value based on the obtained image signal. The control device repeats a transfer operation included in a series of shooting operations in a process in which the series of shooting operations are repeated at the fixed cycle. From the vertical synchronization period until the vertical synchronization period immediately before the vertical synchronization period in which the exposure operation included in the next series of photographing operations is performed, the supply of sub-pulses from the driving device to the solid-state imaging element is repeated. An imaging apparatus comprising sub-pulse stop means.   The solid-state imaging device receives a vertical transfer pulse from the driving device, and transfers a plurality of vertical registers arranged in the vertical direction in the vertical direction, and a vertical transfer pulse from the driving device. And a horizontal register that outputs charges transferred by the plurality of vertical registers, and the pulse supply circuit of the driving device can supply a vertical transfer pulse and a horizontal transfer pulse to the solid-state imaging device. In the series of photographing operations, a vertical transfer pulse and a horizontal transfer pulse are supplied to the solid-state imaging device to transfer charges of pixels in a plurality of columns arranged in the vertical direction to the horizontal register, A transfer operation to be output to the outside is included, and the control device includes the transfer operation in a process in which the series of shooting operations are repeated at the predetermined period. From the vertical synchronization period next to the vertical synchronization period in which the transfer operation is performed to the vertical synchronization period in which the exposure operation included in the next series of imaging operations is performed, a vertical transfer pulse from the driving device to the solid-state image sensor and The imaging apparatus according to claim 1, further comprising transfer pulse stop means for stopping the supply of horizontal transfer pulses.   3. A recording processing circuit for recording an image photographed by the solid-state imaging device on a recording medium, and the series of photographing operations are repeated when an image recording operation is performed by a user. The imaging device described. A solid-state imaging device having an imaging surface composed of a plurality of pixels; a driving device that drives the solid-state imaging device; and a control device that controls the operation of the driving device. The solid-state imaging device receives a sub-pulse from the driving device. In the imaging apparatus including a pulse supply circuit that supplies a sub-pulse to the solid-state imaging device. By supplying a sub-pulse to the element and sweeping out the charge accumulated in the pixel to the outside, an exposure operation for exposing the imaging surface, a transfer operation for transferring the charge accumulated in the pixel by exposure to the outside, and a transfer operation A series of shooting operations including a calculation operation for calculating an exposure time and / or a focus adjustment value based on the obtained image signal. The control device repeats a transfer operation included in a series of shooting operations in a process in which the series of shooting operations are repeated at the fixed cycle. from the vertical synchronization period, until a vertical synchronization period of the immediately preceding vertical synchronizing period exposure operation included in the following series of photographing operation is performed, to reduce the number of supply sub-pulses with respect to the solid-state imaging device from said driving device An imaging apparatus comprising a repeating sub-pulse reduction means.

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